libiberty/concat.c

   1 /* Concatenate variable number of strings.
   2    Copyright (C) 1991, 1994, 2001 Free Software Foundation, Inc.
   3    Written by Fred Fish @ Cygnus Support
   4
   5 This file is part of the libiberty library.
   6 Libiberty is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU Library General Public
   8 License as published by the Free Software Foundation; either
   9 version 2 of the License, or (at your option) any later version.
  10
  11 Libiberty is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 Library General Public License for more details.
  15
  16 You should have received a copy of the GNU Library General Public
  17 License along with libiberty; see the file COPYING.LIB.  If
  18 not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 /*
  23
  24 @deftypefn Extension char* concat (const char *@var{s1}, const char *@var{s2}, @dots{}, @code{NULL})
  25
  26 Concatenate zero or more of strings and return the result in freshly
  27 @code{xmalloc}ed memory.  Returns @code{NULL} if insufficient memory is
  28 available.  The argument list is terminated by the first @code{NULL}
  29 pointer encountered.  Pointers to empty strings are ignored.
  30
  31 @end deftypefn
  32
  33 NOTES
  34
  35         This function uses xmalloc() which is expected to be a front end
  36         function to malloc() that deals with low memory situations.  In
  37         typical use, if malloc() returns NULL then xmalloc() diverts to an
  38         error handler routine which never returns, and thus xmalloc will
  39         never return a NULL pointer.  If the client application wishes to
  40         deal with low memory situations itself, it should supply an xmalloc
  41         that just directly invokes malloc and blindly returns whatever
  42         malloc returns.
  43
  44 */
  45
  46
  47 #ifdef HAVE_CONFIG_H
  48 #include "config.h"
  49 #endif
  50 #include "ansidecl.h"
  51 #include "libiberty.h"
  52 #include <sys/types.h>          /* size_t */
  53
  54 #include <stdarg.h>
  55
  56 # if HAVE_STRING_H
  57 #  include <string.h>
  58 # else
  59 #  if HAVE_STRINGS_H
  60 #   include <strings.h>
  61 #  endif
  62 # endif
  63
  64 #if HAVE_STDLIB_H
  65 #include <stdlib.h>
  66 #endif
  67
  68 static inline unsigned long vconcat_length (const char *, va_list);
  69 static inline unsigned long
  70 vconcat_length (const char *first, va_list args)
  71 {
  72   unsigned long length = 0;
  73   const char *arg;
  74
  75   for (arg = first; arg ; arg = va_arg (args, const char *))
  76     length += strlen (arg);
  77
  78   return length;
  79 }
  80
  81 static inline char *
  82 vconcat_copy (char *dst, const char *first, va_list args)
  83 {
  84   char *end = dst;
  85   const char *arg;
  86
  87   for (arg = first; arg ; arg = va_arg (args, const char *))
  88     {
  89       unsigned long length = strlen (arg);
  90       memcpy (end, arg, length);
  91       end += length;
  92     }
  93   *end = '\000';
  94
  95   return dst;
  96 }
  97
  98 /* @undocumented concat_length */
  99
 100 unsigned long
 101 concat_length (const char *first, ...)
 102 {
 103   unsigned long length;
 104
 105   VA_OPEN (args, first);
 106   VA_FIXEDARG (args, const char *, first);
 107   length = vconcat_length (first, args);
 108   VA_CLOSE (args);
 109
 110   return length;
 111 }
 112
 113 /* @undocumented concat_copy */
 114
 115 char *
 116 concat_copy (char *dst, const char *first, ...)
 117 {
 118   char *save_dst;
 119
 120   VA_OPEN (args, first);
 121   VA_FIXEDARG (args, char *, dst);
 122   VA_FIXEDARG (args, const char *, first);
 123   vconcat_copy (dst, first, args);
 124   save_dst = dst; /* With K&R C, dst goes out of scope here.  */
 125   VA_CLOSE (args);
 126
 127   return save_dst;
 128 }
 129
 130 char *libiberty_concat_ptr;
 131
 132 /* @undocumented concat_copy2 */
 133
 134 char *
 135 concat_copy2 (const char *first, ...)
 136 {
 137   VA_OPEN (args, first);
 138   VA_FIXEDARG (args, const char *, first);
 139   vconcat_copy (libiberty_concat_ptr, first, args);
 140   VA_CLOSE (args);
 141
 142   return libiberty_concat_ptr;
 143 }
 144
 145 char *
 146 concat (const char *first, ...)
 147 {
 148   char *newstr;
 149
 150   /* First compute the size of the result and get sufficient memory.  */
 151   VA_OPEN (args, first);
 152   VA_FIXEDARG (args, const char *, first);
 153   newstr = (char *) xmalloc (vconcat_length (first, args) + 1);
 154   VA_CLOSE (args);
 155
 156   /* Now copy the individual pieces to the result string. */
 157   VA_OPEN (args, first);
 158   VA_FIXEDARG (args, const char *, first);
 159   vconcat_copy (newstr, first, args);
 160   VA_CLOSE (args);
 161
 162   return newstr;
 163 }
 164
 165 /*
 166
 167 @deftypefn Extension char* reconcat (char *@var{optr}, const char *@var{s1}, @dots{}, @code{NULL})
 168
 169 Same as @code{concat}, except that if @var{optr} is not @code{NULL} it
 170 is freed after the string is created.  This is intended to be useful
 171 when you're extending an existing string or building up a string in a
 172 loop:
 173
 174 @example
 175   str = reconcat (str, "pre-", str, NULL);
 176 @end example
 177
 178 @end deftypefn
 179
 180 */
 181
 182 char *
 183 reconcat (char *optr, const char *first, ...)
 184 {
 185   char *newstr;
 186
 187   /* First compute the size of the result and get sufficient memory.  */
 188   VA_OPEN (args, first);
 189   VA_FIXEDARG (args, char *, optr);
 190   VA_FIXEDARG (args, const char *, first);
 191   newstr = (char *) xmalloc (vconcat_length (first, args) + 1);
 192   VA_CLOSE (args);
 193
 194   /* Now copy the individual pieces to the result string. */
 195   VA_OPEN (args, first);
 196   VA_FIXEDARG (args, char *, optr);
 197   VA_FIXEDARG (args, const char *, first);
 198   vconcat_copy (newstr, first, args);
 199   if (optr) /* Done before VA_CLOSE so optr stays in scope for K&R C.  */
 200     free (optr);
 201   VA_CLOSE (args);
 202
 203   return newstr;
 204 }
 205
 206 #ifdef MAIN
 207 #define NULLP (char *)0
 208
 209 /* Simple little test driver. */
 210
 211 #include <stdio.h>
 212
 213 int
 214 main (void)
 215 {
 216   printf ("\"\" = \"%s\"\n", concat (NULLP));
 217   printf ("\"a\" = \"%s\"\n", concat ("a", NULLP));
 218   printf ("\"ab\" = \"%s\"\n", concat ("a", "b", NULLP));
 219   printf ("\"abc\" = \"%s\"\n", concat ("a", "b", "c", NULLP));
 220   printf ("\"abcd\" = \"%s\"\n", concat ("ab", "cd", NULLP));
 221   printf ("\"abcde\" = \"%s\"\n", concat ("ab", "c", "de", NULLP));
 222   printf ("\"abcdef\" = \"%s\"\n", concat ("", "a", "", "bcd", "ef", NULLP));
 223   return 0;
 224 }
 225
 226 #endif